An active layer in a thin film transistor is made of low temperature poly-silicon (LTPS) or amorphous silicon (a-Si). The low temperature poly-silicon has superior physical electrical properties to the amorphous silicon. A complementary metal oxide semiconductor (CMOS) made of the low temperature poly-silicon, which is a gate driver on array (GOA) circuit, may be directly made on a substrate. Adopting a GOA circuit made of the low temperature poly-silicon may reduce the quantity of pins on an external printed circuit board and the quantity of wire connection points, thereby decreasing defects of a display panel, and prolonging its service life.
In the related art, a method for manufacturing low temperature poly-silicon includes Solid Phase Crystallization (SPC), Metal Induced Crystallization (MIC), and Excimer Laser Anneal (ELA), where the ELA is most widely used. In ELA, an excimer laser beam irradiates on an amorphous silicon thin film on the substrate for a while, the amorphous silicon thin film is melted at a high temperature, and melted amorphous silicon is to be cooled and recrystallized rapidly, thereby forming a low temperature poly-silicon thin film.